Dynamic power system adjustment to store energy for power excursions

ABSTRACT

A power system is coupled to a powered system and a system capacitance. The power system includes a power system output sensor, a power conversion device, and a power system output controller. The power system output controller includes a powered system threshold that is related to a power excursion capability of the powered system. The power system output controller is operable, in response to receiving a power system output signal from the power system output sensor that exceeds the powered system threshold, to control the power conversion device to increase the power system output from the power conversion device in order to increase the energy stored in the system capacitance for use by the powered system during a power excursion. The powered system may include processors that draw power from the system capacitance during power excursions so as to not exceed the limits of the power system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation application to U.S. Utility application Ser. No.13/633,700, filed Oct. 2, 2012, entitled “DYNAMIC POWER SYSTEMADJUSTMENT TO STORE ENERGY FOR POWER EXCURSIONS,” Attorney Docket No.16356.1518, the disclosure of which is incorporated herein by referencein their entirety.

BACKGROUND

The present disclosure relates generally to information handling systems(IHSs), and more particularly to dynamically adjusting an IHS powersystem to store energy for power excursions by an IHS.

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option is an IHS. An IHS generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes. Because technology and information handling needs andrequirements may vary between different applications, IHSs may also varyregarding what information is handled, how the information is handled,how much information is processed, stored, or communicated, and howquickly and efficiently the information may be processed, stored, orcommunicated. The variations in IHSs allow for IHSs to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, IHSs may include a variety ofhardware and software components that may be configured to process,store, and communicate information and may include one or more computersystems, data storage systems, and networking systems.

As IHS performance continues to increase, IHS power demands areincreasing to support this increased performance, and are resulting inincreased IHS power excursions that may provide relatively short buthigh peak power demands on the power system. Conventionally, powerexcursions such as, for example, dynamic power (P_(dyn)) and maximumpower (P_(max)) excursions of an IHS processor, drive the sizing of thepower system components. For example, a load integrated circuit (IC) diemay be powered by a voltage regulator that draws its power from avoltage power plane distributed on a motherboard, and that voltage planeis powered from a power supply unit (PSU) in the power system. When ICdie power excursions are relatively low, the voltage regulator cangenerally handle those power excursions without that power demand being“seen” at the PSU (i.e., they do not increase the output current demandfrom the PSU.) However, when the IC die power excursions becomerelatively high, they begin to be seen by the PSU (i.e., they increasethe output current demand from the PSU), and if those power excursionsbecome high enough, a protection circuit in the PSU may be asserted thatwill cause the PSU to shutdown, which may result in data loss. This canoccur due to peak power excursions even when the average power drawn bythe IHS is well below a PSU shutdown threshold. Conventional solutionsto this issue are to provide a power system that is sized for anypossible IHS peak power excursions, which result in costly, oversized,and inefficient power systems that have power output capabilities thatare not needed for the vast majority of system operation, which occursat power levels well below those IHS peak power excursion power levels.

Accordingly, it would be desirable to provide an improved IHS powersystem.

SUMMARY

According to one embodiment, a power system includes a power systemconnector that is operable to couple to a powered system and a systemcapacitance; a power system output sensor coupled to the power systemconnector; a power conversion device coupled to the power systemconnector and operable to provide a power system output to the systemcapacitance and the powered system; and a power system output controllercoupled to the power conversion device and the power system outputsensor, wherein the power system output controller includes a poweredsystem threshold that is related to a power excursion capability of thepowered system, and wherein the power system output controller isoperable, in response to receiving a power system output signal from thepower system output sensor that exceeds the powered system threshold, tocontrol the power conversion device to increase the power system outputfrom the power conversion device in order to increase the energy storedin the system capacitance for use by the powered system during a powerexcursion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating an embodiment of an informationhandling system.

FIG. 2 is a schematic view illustrating an embodiment of a powerexcursion energy storage system.

FIG. 3 is a flow chart illustrating an embodiment of a method fordynamically storing energy in an information handling system (IHS) forpeak power excursions.

FIG. 4 is a graph illustrating an embodiment of power system operationduring the method of FIG. 3.

DETAILED DESCRIPTION

For purposes of this disclosure, an IHS may include any instrumentalityor aggregate of instrumentalities operable to compute, classify,process, transmit, receive, retrieve, originate, switch, store, display,manifest, detect, record, reproduce, handle, or utilize any form ofinformation, intelligence, or data for business, scientific, control,entertainment, or other purposes. For example, an IHS may be a personalcomputer, a PDA, a consumer electronic device, a display device ormonitor, a network server or storage device, a switch router or othernetwork communication device, or any other suitable device and may varyin size, shape, performance, functionality, and price. The IHS mayinclude memory, one or more processing resources such as a centralprocessing unit (CPU) or hardware or software control logic. Additionalcomponents of the IHS may include one or more storage devices, one ormore communications ports for communicating with external devices aswell as various input and output (I/O) devices, such as a keyboard, amouse, and a video display. The IHS may also include one or more busesoperable to transmit communications between the various hardwarecomponents.

In one embodiment, IHS 100, FIG. 1, includes a processor 102, which isconnected to a bus 104. Bus 104 serves as a connection between processor102 and other components of IHS 100. An input device 106 is coupled toprocessor 102 to provide input to processor 102. Examples of inputdevices may include keyboards, touchscreens, pointing devices such asmouses, trackballs, and trackpads, and/or a variety of other inputdevices known in the art. Programs and data are stored on a mass storagedevice 108, which is coupled to processor 102. Examples of mass storagedevices may include hard discs, optical disks, magneto-optical discs,solid-state storage devices, and/or a variety other mass storage devicesknown in the art. IHS 100 further includes a display 110, which iscoupled to processor 102 by a video controller 112. A system memory 114is coupled to processor 102 to provide the processor with fast storageto facilitate execution of computer programs by processor 102. Examplesof system memory may include random access memory (RAM) devices such asdynamic RAM (DRAM), synchronous DRAM (SDRAM), solid state memorydevices, and/or a variety of other memory devices known in the art. Inan embodiment, a chassis 116 houses some or all of the components of IHS100. It should be understood that other buses and intermediate circuitscan be deployed between the components described above and processor 102to facilitate interconnection between the components and the processor102.

Referring now to FIG. 2, an embodiment of a power excursion energystorage system 200 is illustrated. As discussed in further detail below,the IHS power excursion energy storage system 200 may be implemented inor with a variety of IHS's known in the art. For example, the IHS powerexcursion energy storage system 200 may be implemented as part of theIHS 100, discussed above with reference to FIG. 1, which may include aserver IHS, a desktop IHS, a laptop IHS, a tablet IHS, a mobile phoneIHS, and/or a variety of similar IHSs known in the art. In anotherexample, the IHS power excursion energy storage system 200 may beimplemented as a modular IHS such as, for example, a blade server. Assuch, in some embodiments, all of the elements in the IHS powerexcursion energy storage system 200 may be housed in an IHS chassis(e.g., the chassis 116 discussed above with reference to FIG. 1), whilein other embodiments, elements of the IHS power excursion energy storagesystem 200 may be coupled to the IHS (e.g., a plurality of modular IHSsmay be coupled to the power system that may include any combination ofpower supply units (PSUs), power distribution units (PDUs), and/or any avariety of other power system components known in the art, discussed infurther detail below.) Thus, a wide variety of modification to thespecific embodiments discussed below is envisioned as falling within thescope of the present disclosure, including but not limited todistribution of the components across one or more IHSs.

The power excursion energy storage system 200 includes a power system202. While one of skill in the art will recognize that the power system200 discussed below is illustrated and described as a single powersupply unit (PSU) providing power to an IHS and its IHS components, anynumber of PSUs or other power system components may be used to providepower to any number of IHSs having any number of IHS components whileremaining within the scope of the present disclosure. The power system202 includes a power system output controller 204 that, in theillustrated embodiment, includes a master control unit (MCU) 204 acoupled to an output voltage controller 204 b. However, a variety ofdifferent components known in the art may be used to provide the powersystem output controller 204 discussed below. The power system 202 alsoincludes a power conversion device 206 that is coupled to the outputvoltage controller 204 b in the power system output controller 204. Inan embodiment, the power conversion device 206 is operable to receivepower from a power source (e.g., an alternating current (AC) or directcurrent (DC) power source), convert that power (e.g., to a directcurrent (DC) power), and provide the converted power to the poweredsystem including any number of powered components. An output sensor 208is coupled to the power conversion device 206 and the MCU 204 a in thepower system output controller 204. In an embodiment, the output sensor208 is a current sensor that is operable to determine an output currentof the power supply and provide a signal indicative of that outputcurrent.

In an embodiment, the power system 200 includes a power system connector209 that connects the power system to the other components in the powerexcursion energy storage system 200. The power system connector 209 mayinclude a variety of connectors known in the art for connecting a powersystem to a powered system. For example, the power system 202 may beseparate from the IHS, as discussed above, and the power connector 209may include a plug, cables, and/or other power system connectors forconnecting an external power system to an IHS. In another example, thepower system 202 may be integrated with the IHS, discussed above, andthe power connector 209 may include wires, solders, and/or other powersystem connectors for connecting an integrated power system with an IHS.

The power excursion energy storage system 200 also includes a systempower management engine 210 that is coupled to the MCU 204 a in thepower system output controller 204 of the power system 202 (e.g.,through the power system connector 209). In an embodiment, the systempower management engine 210 may be part of an IHS used in the powerexcursion energy storage system 200. The power excursion energy storagesystem 200 also includes a powered system having a plurality of poweredcomponent systems that receive power from the power system 202. In theillustrated embodiment, the powered system is an IHS including aplurality of IHS component systems such as a processor system 210, amemory system 212, and other powered component systems 214 (which may beany IHS component systems such as those illustrated in the IHS 100,discussed above with reference to FIG. 1, and/or a variety of other IHScomponent systems known in the art), each of which is coupled to thepower system 202 (e.g., through the power system connector 209) to allowthose powered component systems to receive power from the power system202. A power component system may include one or more components, one ormore component voltage regulators (i.e., that convert power for use bythe one or more components), and/or a variety of other poweredcomponents devices known in the art. For example, the processor system210 may include one or more processors and one or more processor voltageregulators that convert power received from the power system 202 for useby the one or more processors. Similarly, the memory system 212 mayinclude one or more memory devices and one or more memory device voltageregulators that convert power received from the power system 202 for useby the one or more memory devices. Furthermore, one of skill in the artwill recognize that any component system (e.g., a storage device system,an input/output controller system, a cooling system, etc.) may include(or be coupled to) a component and/or a voltage regulator for convertingpower for use by the component.

In an embodiment, the power excursion energy storage system 200 mayinclude multiple power demand sense points throughout the powered systemthat operate to provide the power system 202 with accurate dataindicative of the the power demand of the powered system and its poweredcomponent systems that accounts for losses in the system such as, forexample, circuit board distribution losses. For example, power demandsensors may be provided by or with the powered component voltageregulators that provide power to significant system loads such as, forexample, the processor voltage regulator discussed above, the memorydevice voltage regulator discussed above, a storage voltage regulator(e.g., that provides power to a storage drive system), a peripheralcomponent voltage regulator (e.g., that provides power to poweredcomponents connected to a Peripheral Component Interconnect express(PCIe) connector), a fan voltage regulator (e.g., that provides power toa fan system), and/or a variety of other point of load (POL) voltageregulators known in the art. Furthermore, a variety of other powerdemand sense points known in the art may include power demand sensorswhile remaining within the scope of the present disclosure.

A system capacitance 216 is illustrated as coupled in parallel betweenthe power system 202 and the powered component systems (e.g., theprocessor system 210, the memory system 212, and the other poweredcomponent systems 214) of the powered system. However, the systemcapacitance 216 included in the power excursion energy storage system200 illustrated in FIG. 2 is provided to represent one or more energystorage devices in the power excursion energy storage system 200, asdiscussed in further detail below. In one embodiment, the systemcapacitance 216 may represent the capacitance included with an IHSmotherboard that is coupled to the power supply unit (PSU) power planein the IHS motherboard. However, in other embodiments, a variety ofdifferent and/or additional capacitance sources may be included in thesystem capacitance 216. For example, the system capacitance 216 mayinclude a power system capacitance that may represent an energy storagecapacity of the power system 202, a powered component capacitance thatmay represent an energy storage capacity of one or more of the poweredcomponents (e.g., the one or more processors in the processor system210, the one or more memory devices in the memory system 212, the one ormore powered components in the other powered component systems 214), apowered component voltage regulator capacitance that may represent anenergy storage capacity of one or more of the powered component voltageregulators (e.g., the one or more processor voltage regulators in theprocessor system 210, the one or more memory device voltage regulatorsin the memory system 212, the one or more powered component voltageregulators in the other powered component systems 214), a boardcapacitance that may represent an energy storage capacity of one or morecircuit boards (e.g., the motherboard coupled to each of the poweredcomponents discussed above and/or other circuit boards in the system.)

Referring now to FIGS. 2, 3, and 4, an embodiment of a method 300 fordynamically storing energy for power excursions is illustrated. Themethod 300 begins at block 302 where a system configuration isdetermined. In an embodiment, the system power management engine 210 maystore or be operable to determine a system configuration that includesthe power usage and/or power demand details of the powered system and/orinformation indicative of the power usage or power demand details of thepowered system. The system power management engine 210 may provide thatsystem configuration to the MCU 204 a in the power system outputcontroller 204. For example, the system power management engine 210included in an IHS may be operable to retrieve (e.g., over a powermanagement bus (PMBus), a system management bus (SMBus), etc.)information about the IHS component systems (e.g., one or moreprocessors in the processor system 210, one or more processor voltageregulators in the processor system 210, one or more memory devices inthe memory system 212, one or more memory device voltage regulators inthe memory system 212, etc.) in an IHS that is indicative of an averagepower demand of the IHS and/or its IHS component systems, a dynamicpower demand of the IHS and/or its IHS component systems, a peak powerdemand of the IHS and/or its IHS component systems, etc. In oneembodiment, the system configuration may include details a powerexcursion capability of one or more processors in the processor system210 (e.g., dynamic power excursions, maximum power excursions, etc.),along with IHS workloads that will be run on the IHS and that willdictate if and when the one or more processors will perform a powerexcursion, the extent of the power excursions that will be performedwhen the IHS is running the IHS workloads, and/or a variety of othersystem configuration information known in the art. In anotherembodiment, the system configuration may also include operating rangesof the powered component systems that indicate a maximum power systemoutput (e.g., an output voltage) of the power system 202 that will stillallow safe operation of the powered component systems in the poweredsystem.

The method 300 then proceeds to decision block 304 where it isdetermined whether the system configuration will result in a powerdemand that exceeds the power system output capability. In anembodiment, the MCU 204 a in the power system output controller 204 isoperable to determine the power system output capability of the powersystem 202. For example, the power system 202 may include protectioncircuits that shut down the power system 202 or otherwise disable powerprovided from the power system 202 to the powered system and its poweredcomponent systems in response to a power demand on the power system 202that exceeds a predetermined power demand amount. As discussed above,due to transient power excursions by powered components in the poweredsystem, those protection circuits may activate to disable power from thepower system 202 even when the average power provided by the powersystem 202 is well below the predetermined power demand amount. At block304, the MCU 204 a may retrieve the power system output capability byretrieving the predetermined power demand amount or other informationthat is indicative of the power output capabilities of the power system202 in providing power to the powered system and its powered componentsystems. Then, using the system configuration determined in block 302,the MCU 204 a may compare the power demands that will be requiredaccording the system configuration and determine whether those powerdemands will exceed the power system output capability during operationof the powered system.

If, at decision block 304, it is determined that the systemconfiguration will not result in power demands that will exceed thepower system output capability of the power system 202, the method 300proceeds to block 306 where the power excursion energy storage system200 may be disabled. For example, for some system configurations, theMCU 204 a in the power system output controller 204 will determine thatthose system configurations include powered component systems andworkloads that will not result in power excursions that exceed the powersystem output capability of the power system 202 and, in response, theMCU 204 a may disable the functionality discussed below such that thepower system 202 will operate as a conventional power system.

If, at decision block 304, it is determined that the systemconfiguration will result in power demands that will exceed the powersystem output capability of the power system 202, the method 300proceeds to block 308 where the power excursion energy storage system isenabled. For example, for some system configurations, the MCU 204 a inthe power system output controller 204 will determine that those systemconfigurations include powered component systems and workloads that willresult in power excursions that exceed the power system outputcapability of the power system 202, and in response, the MCU 204 a mayenable the functionality discussed below such that the power system 202will operate as a conventional power system.

The method 300 then proceeds to block 310 where power system operationlevels and powered system thresholds are set. In an embodiment, usingthe system configuration information determined in block 302 of themethod 300, the MCU 204 a in the power system output controller 204 mayset the power system operation levels of the power system 202. Forexample, as discussed above, the powered component systems (e.g., theprocessor system 210, the memory system 212, the other powered componentsystems 214) may include operating ranges that indicate a maximum powersystem output (e.g., an output voltage) of the power system 202 thatwill still allow safe operation of the powered component systems. Thus,at block 310, the MCU 204 a may set power system operation levels suchthat the power system 202 will not produce a power system output (e.g.,an output voltage) that exceeds the operating ranges of any of thepowered component systems in the powered system, ensuring that theincreased output voltages for the power system 202 discussed belowremain below a maximum level that could cause failure in one or more ofthe powered component systems in the powered system. In an embodiment,the power system operation levels set at block 310 allow the outputvoltage of the power system 202 to be safely adjusted, discussed below,to a maximum amount that still provides for all system load reliabilityrequirements.

In an embodiment, using the system configuration information determinedin block 302 of the method 300, the MCU 204 a in the power system outputcontroller 204 may set powered system thresholds in the power system202. For example, the MCU 204 a may determine from the systemconfiguration that the one or more processors in the processor system210 include a power excursion capability that results in the one or moreprocessors performing power excursions (e.g., dynamic power excursionsand/or peak power excursions) when the IHS is performing its associatedworkloads according the system configuration, and then determine one ormore thresholds that may be used to activate and deactivate the powerexcursion energy storage system 200 in order to power the IHS duringthose power excursions as discussed below. In another example,thresholds set at block 310 may be associated with relatively high andlow power demand operation of an IHS, with the relatively high powerdemand operation associated with transient power excursions that causesa total power demand that exceeds the power system output capabilitiesof the power system 202, and the relatively low power demand operationassociated with a total power demand that is within the power systemoutput capabilities of the power system 202. In an embodiment, thethresholds may be determined and provided to the MCU 204 a by the systempower management engine 210.

FIG. 4 illustrates an embodiment of the operation of the power system202 with a power system operation graph 400 that plots a Power SupplyUnit (PSU) output current 402 and a PSU output voltage 404 vs. time 406.The power system operation graph 400 includes a voltage adjustmentengage threshold 408 that may be one of the powered system thresholdsset at block 310 of the method 300 as discussed above. In theillustrated embodiment, the voltage adjustment engaged threshold 408includes a power demand (e.g., a current drawn) by the IHS that causesthe power excursion energy storage system 200 to begin to generateenergy for storage and use by the powered system and its poweredcomponent systems during a power excursion, discussed in further detailbelow. The power system operation graph 400 also includes a voltageadjustment disengage threshold 410 that may be one of the powered systemthresholds set at block 310 of the method 300 as discussed above. In theillustrated embodiment, the voltage adjustment disengage threshold 410includes a power demand (e.g., a current drawn) by the IHS that causesthe power excursion energy storage system to cease generating energy forstorage and use by the powered system and its powered component systemsduring a power excursion, discussed in further detail below. In theillustrated embodiment, the voltage adjustment engaged threshold 408 andthe voltage adjustment disengage threshold 410 are separated by a powerdemand amount (e.g., an amount of current demanded by the IHS) toprovide hysteresis and avoid oscillating behavior during power delivery.While a few examples of powered system thresholds have been provided,one of skill in the art will recognize that a variety of thresholds withfall within the scope of the present disclosure to provide thefunctionality discussed below.

In an embodiment, the blocks 302, 304, 306 or 308, and 310 of the method300 may be performed in response to the start-up or powering-on of anIHS. For example, some IHS's may include different operating profilesthat include different workloads for operation on the IHS, and thus theblocks 302, 304, 306 or 308, and 310 of the method 300 may be performedto enable or disable the power excursion energy storage system 200depending on whether the operating profile will cause power excursionsthat will exceed the power system output capability of the power system202. In another example, an IHS may periodically or occasionally haveits powered component systems or other components changed, or havedifferent workload installed, and thus the system configuration of thatIHS may periodically or occasionally change. Thus, the blocks 302, 304,306 or 308, and 310 of the method 300 may be performed regularly or uponperiodic/occasional changes to the IHS to determine whether thosechanges will require the power excursion energy storage system 200 toallow the power system 202 to sufficiently power the powered componentsystems. In yet another example, the blocks 302, 304, 306 or 308, and310 of the method 300 may be performed once for an IHS that not expectedto have its powered component systems or other components changed,and/or that performs the same workloads regularly, and the blocks 302,304, and 306 or 308 of the method 300 may either not be performed again,or only may be performed in response to a detected change in the IHS orinstruction from a user of the IHS.

The method 300 then proceeds to block 312 where a power system outputsignal is monitored. In an embodiment, subsequent to the setting of thepower system operation levels and powered system thresholds for thepower system 202, the powered system and its powered component systemsmay operate according to the system configuration. For example, in anIHS, the processor system 210, the memory system 212, and the otherpowered systems 214 may operate to perform workloads for the IHSaccording to the IHS configuration. During normal operation of thepowered system that does not include power excursions by the poweredsystem or powered component systems that exceed a power outputcapability of the power system 202, the power system 202 provides poweraccording to a default set point voltage. For example, the power systemoperation graph 400 illustrates how, up to a time 412, the power system202 provides a PSU output voltage 404 of 12 volts. As can be seen fromthe power system operation graph 400, with the PSU output voltage 404 at12 volts, the powered system and its powered component systems may drawa varying current.

During operation of the powered system, the output sensor 208 in thepower system 202 is operable to measure a power system output of thepower system 202 and provide a signal to the MCU 204 a in the powersystem output controller 204 that is indicative of the power demand ofthe powered system. For example, the output sensor 208 may be a currentsensor that that provides a signal to the MCU 204 a that is indicativeof the current draw of the IHS including the processor system 210, thememory system 212, and the other system components 214 (e.g., the PSUoutput current 402 illustrated in the power system operation graph 400of FIG. 4). In another example, power demand sensors at a plurality ofsense points in the IHS may operate to provide the MCU 204 a withinformation indicative of the power demand of the powered componentsystems as well.

The method 300 then proceed to block 314 where it is determined whetherthe power system output signal exceeds a threshold. As discussed withreference to block 310, the MCU 204 a sets one or more thresholds forthe power system 202 that may be used to activate and deactivate thepower excursion energy storage system 200. If at decision block 314, theMCU 204 a determines that the power system output signal has notexceeded a threshold (e.g., the voltage adjustment engaged threshold 408illustrated in the power system operation graph 400 of FIG. 4), themethod 300 returns to block 312 to monitor the power system outputsignal.

If at decision block 314, the MCU 204 a determines that the power systemoutput signal has exceeded a threshold (e.g., the voltage adjustmentengaged threshold 408 illustrated in the power system operation graph400 of FIG. 4), the method 300 proceeds to block 316 where the powersystem output is temporarily increased to charge the system capacitance.The power system operation graph 400 illustrates how, at time 412 andpoint A on the graph 400, the PSU output current 402 increases above thevoltage adjustment engaged threshold 408. This increase is accompaniedby a power system output signal from the output sensor 208 to the MCU204 a that is indicative of that PSU output current 402, and at decisionblock 314, the MCU 204 a determines that the power system output signalhas exceeded the voltage adjustment engaged threshold 408. In responseto determining the PSU output current 402 has exceeding the voltageadjustment engaged threshold 408, the MCU 204 a sends a signal to theoutput voltage controller 204 b that causes the output voltagecontroller 204 b to control the power conversion device 206 such thatthe power conversion device 206 increases the power system output of thepower system 202 (e.g., by setting an output voltage set point in thepower conversion device 206 to a desired voltage).

For example, as can be seen in the power system operation graph 400,prior to time 412, the power system 202 provides a PSU output voltage404 of 12.0 volts. However, when the PSU output current 402 exceeds thevoltage adjustment engaged threshold 408, the output voltage controller204 b controls the power conversion device 206 to increase the PSUoutput voltage 404 from 12.0 volts at point B on the graph 400 to 12.5volts at point C on the graph 400. In an embodiment, the output voltagecontroller 204 b may control the power conversion device 206 to increasethe power system output at a predefined ramp rate. As can also be seenfrom the power system operation graph 400, while the PSU output current402 remains above the voltage adjustment disengage threshold 410, thepower conversion device 206 operates such that the PSU output voltage404 remains at 12.5 volts between points C and E on the graph 400.However, at point D on the graph 400, the PSU output voltage 402 fallsbelow the voltage adjustment disengage threshold 410. This decrease isaccompanied by a power system output signal from the output sensor 208to the MCU 204 a that is indicative of that PSU output current 402 andresults in the MCU 204 a determining that the power system output signalhas decreased below the voltage adjustment disengage threshold 410. Inresponse to determining that the PSU output current 402 has decreasedbelow the voltage adjustment disengage threshold 410, the MCU 204 asends a signal to the output voltage controller 204 b that causes theoutput voltage controller 204 b to control the power conversion device206 such that the power conversion device 206 decreases the power systemoutput. Thus, at point E on the graph 400, the PSU output voltage 404 isallowed to decay back to 12.0 volts.

Thus, when the powered system and its powered component systems operatesuch that a power system output signal indicates that a threshold isbeing exceeded, the power system output is temporarily increased (i.e.,for as long as the powered system and its powered component systems areoperating such that they may produce a power demand that exceeds thepower output capability of the power system 202). This increase in powersystem output is used to charge the system capacitance 216 at block 316of the method 300. The system capacitance stored charge relationshipwith the power system output voltage is governed by the equation:

U=½CV ²

where C is the value of the system capacitance (e.g., in Farads) and Vis the power system output (e.g., in Volts.) With the squaredrelationship between power system output and the system capacitancestored charge, the calculation below gives the following systemcapacitance stored charge for operation of the power system 202 at 12volts with a system capacitance of 20 μFarads:

U ₁=½(20×10⁻⁶ farads)(12 volts)²=0.0014 coulombs

The calculation below illustrates the increase in system capacitancestored charge for operation of the power system 202 at 13 volts with asystem capacitance of 20 μFarads:

U ₂=½(20×10⁻⁶ farads)(13 volts)²=0.0017 coulombs

Thus, as can be seen, a 1 volt increase in the power system outputyields an approximately 20% increase in the system capacitance storedcharge. One of skill in the art will recognize that the systemcapacitance and power system output may be sized and/or modified for aparticular system configuration in order to allow the system to store anamount of charge in the system capacitance that is sufficient to powerthat system configuration through a predetermined maximum power demandexpected as a result of power excursions (e.g., dynamic and/or peakpower excursions.)

The method 300 then proceeds to block 318 where power is provided fromthe system capacitance for a power excursion by the powered systemand/or one or more of its powered component systems. As discussed abovewith regard to block 316, the power system 202 operates to generate astored charge in the system capacitance 216 when the powered systemand/or powered component system operation exceeds a threshold. As alsodiscussed above, that threshold may be associated with a power excursionby the powered system and, more particularly, by one or more of thepowered component systems in the powered system. Thus, as those one ormore of the powered component systems begins or approaches a powerexcursion, the power system 202 operates to provide additional storedcharge in the system capacitance 216 for use by the powered system andits powered component systems. Thus, when a powered component systemperforms the power excursion such that the power demand from the poweredsystem and its powered component system would otherwise cause the powersystem 202 to exceed its power system output capability, the powersystem 202 instead provides a power system output to the powered systemand its powered component systems that is at or below its power systemoutput capability, and the powered system and its powered componentsystems are powered with additional power up to the power excursionamount demanded using the stored charge in the system capacitance 216.

In one example, a processor in the processor system 210 includes a powerexcursion capability that includes temporary dynamic power excursionsand peak power excursions that provide a total power demand on the powersystem 202 that exceeds the power system output capability. The powersystem 202 is operable to determine that the power excursions by theprocessor will occur and, in response, increase the power system outputvoltage to generate an additional stored charge in the systemcapacitance 216. When the processor performs the power excursion, thepower used to power the processor is provided by the power system 220,operating within its power system output capability, and the storedcharge in the system capacitance 216. When the power demand on the powersystem 202 then drops below a threshold, the power system 202 decreasesits power system output voltage back to the original level. Thus, thepower excursion energy storage system 200 is operable to repeatedlyincrease the power system output of the power system 202 to provide theadditional stored charge in the system capacitance 216 for use by theprocessor during dynamic and/or peak power excursions, and then decreasethe power system output of the power system 202 when those dynamicand/or peak power excursions are no longer present or no longer wouldresult in the power system 202 operating beyond its power system outputcapability.

Thus, a system and method have been described that allow a power systemto be appropriately sized for the average power requirements of aninformation handling system. When the information handling systemperforms power excursions that may be well above the average powerrequirements for a temporary but significant amount of time, the powersystem operates to generate a charge in the system capacitance that isthen used, along with a power system output of the power system that isat or below its maximum power system output capability, to power theinformation handling system through the power excursion. Such systemsand methods allow the provision of a smaller and more efficient powersystem that is appropriate for a majority of the operation conditionsthat will be experienced by the information handling system, whileallowing the information handling system to be supplied sufficient powerduring transient, high power demand situations such that no performancedegradation exists due to the use of the smaller and more efficientpower system.

Although illustrative embodiments have been shown and described, a widerange of modification, change and substitution is contemplated in theforegoing disclosure and in some instances, some features of theembodiments may be employed without a corresponding use of otherfeatures. Accordingly, it is appropriate that the appended claims beconstrued broadly and in a manner consistent with the scope of theembodiments disclosed herein.

What is claimed is:
 1. A power system, comprising: a power systemconnector that is configured to couple to a powered system and a systemcapacitance; a power conversion device coupled to the power systemconnector and configured to provide a power system output to the systemcapacitance and the powered system; and a power system output controllerthat is coupled to the power conversion device and configured to:control the power conversion device to provide a first power systemoutput level to the system capacitance and the powered system; anddetermine that the powered system will exceed a power system outputcapability of the power system in response to performing a workload and,in response, control the power conversion device to increase the firstpower system output level from the power conversion device to a secondpower system output level in order to increase the energy stored in thesystem capacitance to a level that provides sufficient power for thepowered system to perform the workload without exceeding the powersystem output capability of the power system.
 2. The power system ofclaim 1, wherein the first power system output level is a default setpoint voltage provided by the power conversion device.
 3. The powersystem of claim 1, wherein the power system output controller isconfigured to provide an output voltage set point in the powerconversion device to increase the first power system output level to thesecond power system output level.
 4. The power system of claim 1,wherein the increase of the first power system output level from thepower conversion device to the second power system output level isperformed at a predefined ramp rate.
 5. The power system of claim 1,wherein the second power system output level is provided by the powerconversion device throughout the powered system performing the workload.6. The power system of claim 1, wherein the level of energy stored inthe system capacitance due to the second power system output level fromthe power conversion device is based on a maximum power demand expecteddue to the powered system performing the workload.
 7. The power systemof claim 1, wherein the system capacitance includes a power systemcapacitance of the power system, a powered component capacitance ofpowered components in the powered system, a powered component voltageregulator capacitance of powered component voltage regulators in thepowered system, and a board capacitance of the powered system.
 8. Aninformation handling system (IHS), comprising: a processing system; asystem capacitance coupled to the processing system; and a power systemcoupled to the processing system and the system capacitance; and a powersystem output controller that is included in the power system andconfigured to: control the power system to provide a first power systemoutput level to the system capacitance and the processing system; anddetermine that the processing system will exceed a power system outputcapability of the power system in response to performing a workload and,in response, control the power system to increase the first power systemoutput level from the power system to a second power system output levelin order to increase the energy stored in the system capacitance to alevel that provides sufficient power for the processing system toperform the workload without exceeding the power system outputcapability of the power system.
 9. The IHS of claim 8, wherein the firstpower system output level is a default set point voltage provided by thepower system.
 10. The IHS of claim 8, wherein the power system outputcontroller is configured to provide an output voltage set point in thepower system to increase the first power system output level to thesecond power system output level.
 11. The IHS of claim 8, wherein theincrease of the first power system output level from the power system tothe second power system output level is performed at a predefined ramprate.
 12. The IHS of claim 8, wherein the second power system outputlevel is provided by the power system throughout the processing systemperforming the workload.
 13. The IHS of claim 8, wherein the level ofenergy stored in the system capacitance due to the second power systemoutput level from the power system is based on a maximum power demandexpected due to the processing system performing the workload.
 14. TheIHS of claim 8, wherein the system capacitance includes a power systemcapacitance of the power system, an IHS component capacitance of IHScomponents in the IHS, a voltage regulator capacitance of voltageregulators in the IHS, and a board capacitance of a circuit board in theIHS.
 15. A method for dynamically storing energy in an informationhandling system (IHS) for power excursions, comprising: controlling apower system to provide a first power system output level to a systemcapacitance and a powered system; determining that the powered systemwill exceed a power system output capability of the power system inresponse to performing a workload and, in response, increasing the firstpower system output level from the power system to a second power systemoutput level; and increasing the energy stored in the system capacitanceusing power provided by the power system at the second power systemoutput level, wherein the energy stored in the system capacitance isincreased to a level that provides sufficient power for the poweredsystem to perform the workload without exceeding the power system outputcapability of the power system.
 16. The method of claim 15, wherein thefirst power system output level is a default set point voltage providedby the power system.
 17. The method of claim 15, wherein the powersystem output controller is configured to provide an output voltage setpoint in the power system to increase the first power system outputlevel to the second power system output level.
 18. The method of claim15, wherein the increase of the first power system output level from thepower system to the second power system output level is performed at apredefined ramp rate.
 19. The method of claim 18, wherein the secondpower system output level is provided by the power system throughout thepowered system performing the workload.
 20. The method of claim 15,wherein the level of energy stored in the system capacitance due to thesecond power system output level from the power system is based on amaximum power demand expected due to the powered system performing theworkload.